Docker ignoring platform when run in NixOS

18

As of nixos/binfmt: Add option to use static emulators when available by jcaesar · Pull Request #334859 · NixOS/nixpkgs · GitHub
Setting:

  boot.binfmt = {
    emulatedSystems = [ "aarch64-linux" ];
    preferStaticEmulators = true; # Make it work with Docker
  };

Just Works™

Unfortunately that is not on stable yet, but the following works on stable (using the fixed unstable packages as pkgsUnstable):

  boot.binfmt =
    let
      system = "aarch64-linux";
    in
    {
      emulatedSystems = [ system ];
      registrations.${system} = {
        interpreter = (pkgsUnstable.lib.systems.elaborate { inherit system; }).emulator pkgsUnstable.pkgsStatic;
        fixBinary = true;
      };
    };

Either way (stable or unstable), setting registrations.aarch64-linux.matchCredentials = true will typically be useful as well if using suid binaries.

1 Like